A primer on the mouse basal body

Abstract

The basal body is a highly organized structure essential for the formation of cilia. Basal bodies dock to a cellular membrane through their distal appendages (also known as transition fibers) and provide the foundation on which the microtubules of the ciliary axoneme are built. Consequently, basal body position and orientation dictates the position and orientation of its cilium. The heart of the basal body is the mother centriole, the older of the two centrioles inherited during mitosis and which is comprised of nine triplet microtubules arranged in a cylinder. Like all ciliated organisms, mice possess basal bodies, and studies of mouse basal body structure have made diverse important contributions to the understanding of how basal body structure impacts the function of cilia. The appendages and associated structures of mouse basal bodies can differ in their architecture from those of other organisms, and even between murine cell types. For example, basal bodies of immotile primary cilia are connected to daughter centrioles, whereas those of motile multiciliated cells are not. The last few years have seen the identification of many components of the basal body, and the mouse will continue to be an extremely valuable system for genetically defining their functions.

Once and only once: mechanisms of centriole duplication and their deregulation in disease

“…The wall of a fully mature centriole carries two sets of appendages: subdistal appendages, which are required for anchoring of cytoskeletal microtubules, and distal appendages, which are needed for membrane docking during ciliogenesis. Several appendage markers have been identified, but much remains to be learned about the assembly and function of these structures 13,14 . The proximal part of the procentriole [G] lumen harbors a scaffolding structure known as the ‘cartwheel’ (Figure 1A) 15 , whose assembly represents the first step in the construction of a new procentriole and onto which microtubules are added to form the centriolar wall.…”

The PLK4–STIL–SAS-6 module at the core of centriole duplication

“…Centrioles are barrels composed of microtubule triplets arranged in nine-fold rotational symmetry [5,10,11]. They are important not only for the assembly of centrosomes, but indispensable also (as so-called basal bodies) for the formation of cilia and flagella [12,13]. …”

HIF Stabilization Weakens Primary Cilia

“…Primary cilium structure consists of 9 microtubule doublets anchored in the basal body, which itself is a highly organized structure comprising the centrosomes (microtubule triplets), transition fibers, a rootlet, and the basal foot [25] known collectively as the microtubule organizing center. We hypothesize that the mechanosensing function of cilia can occur by straining these microtubule structural elements in a similar manner to actin-mediated mechanosensation [26].…”